1. Field of the Invention
The present invention relates to a power-control device capable of automatically supplying power when a user simply holds the power-control device with a hand of the user, an electronic apparatus including the power-control device, and a method for activating the electronic apparatus. More particularly, the present invention relates to a power-control device in which a capacitance-type touch sensor is used, an electronic apparatus including the power-control device, and a method for activating the electronic apparatus.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2004-312477 discloses a camera apparatus in which a power-control device, which is capable of automatically supplying power at a timing based on an intention of a user, is mounted.
This camera apparatus includes a directional sensor, which detects the vertical and horizontal directions of a body of the camera apparatus, a light sensor, which detects ambient brightness, a vibration sensor, which detects vibration, or a touch sensor, which detects that a user touches a specified portion of the body of the camera apparatus. When the output of each of the sensors is changed on the basis of a corresponding detection, power of the camera apparatus is automatically supplied.
However, it is difficult to ensure a stable activation in a configuration with only one directional sensor. More specifically, in a configuration with the touch sensor, in order to reliably activate the camera apparatus, the user must touch the specified portion of the camera apparatus, in which the touch sensor is mounted, or must continue touching the specified portion until power is supplied or the activation is confirmed. Accordingly, unfortunately, the operability of the camera apparatus is poor.
For this reason, in Japanese Unexamined Patent Application Publication No. 2004-312477, for example, a configuration with a combination of the directional sensor and the light sensor (in the third embodiment), a configuration with a combination of the directional sensor and the vibration sensor (in the forth embodiment), a configuration with a combination of the direction sensor and the touch sensor (in the fifth embodiment), and a configuration with a combination of the light sensor and the touch sensor (in the six embodiment) are described. In other words, the stabilization of the activation is designed by using a plurality of sensors including two or more types of sensors.
However, in the above-described configurations, each of which uses a combination of a plurality of sensors including two or more types of sensors, a complicated control circuit for the sensors is necessary, and an additional software program used to control the sensors is also necessary. Accordingly, the manufacturing cost is markedly increased.